Reliability Analysis of Wireless Sensor Networks

Wireless smart sensors, with self-diagnosis and self-calibration capabilities, have drawn much attention for structural health monitoring (SHM) applications. Low-cost wireless smart sensor networks (WSSN) can facilitate densely distributed sensing on full-scale civil structures. However, limited radio power and obstacles preventing line-of-sight communication, along with high sampling rates and large data transfer demands, make using WSSN for SHM a challenging problem. Current WSSN deployment strategies are often fault-tolerant, accommodating node failure during communication and compensating loss of sensor nodes during communication by having densely distributing sensors in the network. In this paper, the joint relationship between the measured link quality indicator (LQI) and the radio signal strength indicator (RSSI) in a single-hop network will be investigated to assess packet reception rate (PRR). In addition, a new mathematical model of PRR is proposed to describe data transfer of wireless sensor pairs in terms of LQI and RSSI. Both the first-order-reliability method (FORM) and Monte Carlo Simulation (MCS) are then used for reliability analysis of the wireless sensor network. System reliability analysis is also performed to examine the reliability of multi-hop networks.